Continuous process for reacting a basic group h metal compound and a phosphorus acid



Aug. 8, 1967 c:

F. CONTINUOUS PROCESS FOR R GOLDSMITH 3,335,158

EACTING A BASIC GROUP II METAL COMPOUND AND A PHOSPHORUS ACID Filed Oct.23, 1961 INVENTOR.

FRED CORWIN GOLDSMITH 0mm, m 4 Homily ATTORNEYS 3,335,l53 Patented Aug.8, 1 967 Fred Cor-win Goldsmith, Painesville, Ohio, assignor to TheLubrizol Corporation, Wicklifie, Ohio, a corporation of Qhio Filed Oct.23, 1961, Ser. No. 132,316 4 Claims. (Cl. 260429.9)

This invention relates as indicated to a process and apparatus forreacting a plurality of reagents, at least one of which is a liquid, andat least one of which is a solid, and more particularly wherein thespecific gravities of said fluid and solid reagents are substantiallydifferent.

This application is a continuation-inpart of application Ser. No.723,922, filed Mar. 25, 1958, and now abandoned, said abandonedapplication having in turn been filed as a continuation-in-part ofapplication Ser. No. 262,600, filed Dec. 20, 1951, and now US.2,862,947. This application is a continuation-in-part also ofapplication Ser. No. 680,882 (now U.S. 3,086,849), filed Aug. 28, 1957,which application is a division of the above application Ser. No.262,600.

By the present invention, the reaction is carried out with the reagentsin the form of a slurry which is continuously circulated. By continuousor intermittent replenishment of the reagents taken up by the reactionand preferably also by the continuous or intermittent withdrawal of theproducts formed, the process may be made fully continuous.

The process and apparatus of this invention are adapted for use withboth endothermic and exothermic reactions since it is relatively easy toeffect the necessary temperature control as by heating or cooling of thereaction mass as it is circulated.

As indicated, the invention is particularly adapted for use in reactionswherein the reagents have measurable diiferences in specific gravity andespecially in connection with reactions which permit the presence in thereaction mass of substantial excesses of one of the reagents, since bymaintaining those conditions it has been found possible to control therate of replenishment of the reagents by such simple means as densityresponsive equipment.

More particularly, the invention is applicable to reactions such asthose in which a solid such as a phosphorus sulfide is reacted with anorganic hydroxy compound such as an alcohol, phenol, or naphthol in theproduction of phosphorodithioic acids. The invention is applicable alsoto the preparation of metal salts of organic acids such asphosphorodithioic acids and sulfonic acids.

It is therefore a principal object of this invention to provide aprocess by which reactions of the character defined may be carried outexpeditionsly, at low cost, and by the use of simple equipment which maybe readily controlled.

Other objects of the invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said inventionthen comprises the features hereinafter fully described and particularlypointed out in the claims, the following description and the annexeddrawing setting forth in detail certain illustrative embodiments of theinvention, these being indicative, however, of but a few of the variousways in which the principle of the invention may be employed.

Broadly stated, this invention comprises the process of reacting solidand liquid reagents to form a liquid product, including the steps ofcontinuously circulating in a closed system a slurry of at least onesolid reagent, the

mapor portion of the liquid phase of said slurry being inert to thedesired reaction, introducing into said closed system at least oneliquid reagent at rates so as to maintain said solid reagent at everypoint in said .system in amounts greatly in excess of the minimumamounts required for complete reaction with the amount of liquid reagentpresent at that point, maintaining the temperature of the continuouslycirculating stream of slurry for a substantial portion of itscirculating cycle at a temperature favorable to the desired reaction,and drawing off from the system liquid product at about its rate offormation.

Referring now more particularly to the preferred form of my invention inthe drawing, one hundred gallons of slurry 1, comprising solid reagentssuch as a phosphorus sulfide suspended in a mixture of a smallproportion of liquid reagent such as an alkylated .hydroxyaromaticcompound and a relatively large proportion of a diluent, which can be aninert material or preferably the liquid product of the reaction of thesolid reagent with the liquid reagent, is maintained at a uniformtemperature in reactor 2. The solid reagents form the solid phase andthe diluent the liquid phase of the slurry. The slurry is agitated inthe kettle by stirrer 3 and vanes 7 attached to the Wall of the kettle.The powdered solid reagent is loaded into feed hopper 4 located abovereactor 2. The solid reagent is continuously fed into the reactor 2 fromhopper 4 by means of a revolving vertical screw 5 extending into the topof the reactor. The screw 5 fits the barrel 6 of the hopper 4 closelyand provides gas-tight seal between hopper 4 and kettle 2. The liquidreagent is continuously fed into the slurry by line 8 connected to line9, or if desired by a line connected into the top of re actor 2. Theliquid reagent and solid reagent react in reactor 2, forming a liquidproduct and liberating a gas. A vertical weir 10 is provided in reactor2. A bafiie 11 is spaced from weir 10 and provides a quiescent zonearound the weir 10. A portion of the slurry in the reactor overfiowscontinuously weir 10 and flows down line 20 into solids separator 12located below the reactor. The decanted liquid phase of the slurry,essentially free of solid reagent, overflows the side of separator 12,into the receiver 13. The solid reagent enriched separator slurry streamis fed to a pump 14 and returned to the reactor 2 by line 9. The liquidphase of the slurry is pumped from the receiver 13 by pump 22 tosuitable storage tanks, not shown. If the diluent is a material otherthan the reaction product of the solid and liquid reagents, furthersteps will have to be taken to separate the diluent and product. Forthis purpose a flash evaporator 60 can be employed to evaporate thediluent and conduct the diluent vapor by line 61 to cooler 18 where thediluent is condensed and returned to the slurry by line 19. Thus, it isdesirable for most purposes to use where possible the reaction productas the diluent.

The lay-product gas atmospheres in the reactor 2, separator 12, andreceiver 13 are collected in lines 14A, 15, 16, respectively, connectedto common line 17. The byproduct gas liberated is normally saturatedwith evaporated liquid reagent. The gas stream is passed by common line17 to gas cooler 18, and the liquid reagent condensate is run back intoreactor 2 by line 19. The cooled gas then passes to an absorber by line21, not shown, or is disposed of in some other way.

The specific gravity of the solid reagent is substantially differentfrom the liquid phase of the slurry so that, as the concentration ofsolid reagent in the slurry increases, the density increases; and as theconcentration of solid reagent in the slurry decreases, the density decreases. Thus, the measured density provides a means for controlling thefeed ratios of the reagents. The liquid reagent feed may be keptconstant and the solid reagent feed varied, or the solid reagent feedmay be held constant and the liquid reagent feed varied. The firstmethod is used in this unit, but the latter method may be used equallywell.

The solid reagent should have a specific gravity 4 dithioic acid and Pis continuously circulated from reactor 2, over weir 10, to separator12, and then back to reactor 2 by pump 14- and line 9. When the densityof the slurry increases in reactor 2 above a certain value, an automaticcontrol shuts the P S feed off until the that is substantially differentfro mthe liquid phase of 5 density falls below a particular point, atwhich time the the slurry. In the process and apparatus of thisinvention P 8 feed is resumed automatically. The P 5 is mainit isdesirable to employ a solid reagent with a specific tained at everypoint in the system in amounts greatly gravity substantially greaterthan the specific gravity of in excess of the minimum amounts requiredfor comthe liquid phase of the slurry. plete reaction with the alcoholpresent at that point.

The solid reagent employed should be in afinely divided Thus, thealcohol when introduced into the slurry reacts state, and it ispreferable to use a solid reagent which almost immediately with the P 5to insure accurate will pass through No. 20 US. Standard Screen. controlof the rates of feed by the densometer. The organo In the preparation ofphosphorus thioic acids the solid phosphorodithioic acid is decantedessentially free of reagent can be a phosphorus sulfide, for example:111 5 from separiator 12 to receiver 13. It has 1beelii 1fofunc t at itis equaly satisfactory to vary the aco o -ee rate while maintainingconstant the P 8 feed rate.

Ph p 4 6 2 3 While the above data relate to the reaction of phososphorussesquisulfide-P S h t Ifid d 1 h 1 th b1 Phosphorous pntaSu1fide P2S(P481 p orus pen asu e an a co 0 s, e process is app ica e 5 0 lso tothe reaction of phosphorus sulfides and hydroxy- PhosphorusheptasulfideP S a aromatic compounds such as phenols and naphthols. ThisFor many purposes, phosphorous pentasulfide will b is rather unexpectedbecause, although the chemistry of the found especially useful as asolid reagent. reaction of phenolic com-pounds with phosphorus penta-The liquid reagent, in Such B P p y be an sulfide is analogous to thechemistry of the reaction of alkylated hydroxyaromfitic Compound, allalkylated alcohols with phosphorus pentasulfide, the engineeringphenolic compound. Thus it may be an alkylated ph n l features of thetwo reactions are obviously quite dis- Of an alkylated naphthol;illustrative examples include similar. Alcohols diifer markedly fromphenolic comblltyl Phenol, octyl P dodecyl P octadecyl pounds not onlyas to their physical properties, viz., al- Phellol, y fip fip a-eicosylcohols generally are liquids whereas phenolic compounds 8-naphthol, andpolyisobutyl-substituted -naph hol n are for the most part solids, butalso in their relative which the polyisobutyl substituent is derivedfrom a polychemical activities. isoblltene having an average molecularWeight of The process of this invention was found to be satis- If thealkylated hydfoxyafomatic Compound is a Solid factorily operable forreactions involving hydroxyaromatic it can be dissolved in an inertsolvent and in that mancom-pounds, particularly alkylatedhydroxyaromatic comner be employed as a liquid reagent in the process.pounds, with phosphorus sulfides generally.

The liquid reagent may also be an alcohol, for example As indicatedabove, the preparation of metal salts of a monohydric or dihydricalcohol. The following table the aromatic and aliphatic substitutedphosphorodithioic summarizes typical operating conditions in the processacids may be effected in the same manner and in the and apparatusdescribed above for the preparation of same apparatus as the acids.Likewise, metal salts of other phosphorodithioic acids by the reactionof P 8 and variorganic acids, e.g., metal sulfonates, can be prepared inous alcohols. this fashion. In such cases the solid reagent is a basicType of Alcohol Item Condition go gigggl Blend 1 binol A Alcoholfeedrate,lbs./hr 472 277 700 P285 feed rate, lbs./hr 244 244 293 Acidrate, lbs /hr 619 483 943 H S rate, lbs/hr..." 37 38 Operating Temp., F210 210 Operating Density (1955-0972 1 [MO-1.058 0 9l80.936 Percent Pas,in slurry 6-8 1 Blend, 37.5% n-octyl alcohol, 37.5% methyl-iso-butylcarbinol, 25% n-hexyl alcohol.

To persons skilled in the art, a description of the operation of theprocess and apparatus constituting the present invention will be founduseful. In the preparation of phosphorodithioic acids by the reaction ofP S and alcohols or alkylated hydroxyaromatic compounds, the reaction isillustrated by the following equation:

The liquid phosphorodithioic acid is preferred as the diluent in thisprocess. The alcohol is fed into reactor 2 heated to reactiontemperature (see item B in the table above) after the alcohol overflowsweir 10, the alcohol is shut off. The P 8 feed is begun (see item B inthe table above), and as the density approaches the desired range (seeitem F above) the alcohol feed is begun at one-half the normal feed rate(see item A above). Over a four hour period the alcohol feed rate isgradually increased to normal. The slurry, comprising essentiallyphosphoroinorganic compound and the liquid reagent is aphosphorodithioic or sufonic acid.

Suitable metal salts include those of metals in Groups I, II and III ofthe Periodic Table and especially the alkali metals, alkaline earthmetals, and zinc.

An illustrative preparation of zinc phosphorodithioate by this processis a preparation of the zinc salt of a phosphorodithioic acid preparedin turn by the reaction of four moles of a 65:35 molar mixture ofisobutyl and primary amyl alcohols with 1.0 mole of P 8 The solidreagent in this particular reaction is the zinc oxide and the liquidreagent is a solution consisting of 69.5 parts of the correspondingphosphorodithioic acid, 10.6 parts of mineral oil, and 19.9 parts of a65:35 molar mixture of isobutyl and primary amyl alcohols. Thetemperature of the process mixture is maintained at 195 F. throughoutthe period of reaction.

An illustration of the applicability of the process to the preparationof the metal sulfonate is the preparation of a zinc sulfonate. Hereagain the solid reagent is zinc oxide; the liquid reagent is a solutionof 22 percent by weight of petroleum sulfonic acid in 25 percent ofisopropyl alcohol, and 50.5 percent of mineral oil (2.5 percent ofsodium petroleum sul-fonate being present as an impurity). Thetemperature of the reaction in this example is 135-140 F.

The above examples illustrate the wide applicability of the process ofthis invention and it is thus apparent that the process can readily beadapted to the preparation of such metal salts as calcium sulfonates,barium sulfonates, magnesium sulfonates, sodium sulfonates, calciumphosphorodithioates, barium phosphorodithioates, potassiumphosphorodithioates, etc.

Illustrative examples of pairs of liquid reagents and solid reagentswhich are reacted advantageously according to the process of thisinvention are shown below.

*Polybutenc of about 750 molecular weight.

What is claimed is:

1. In the process of reacting a basic Group II metal compound andphosphinodithioic acid to form a liquid product, the steps ofcontinuously circulating in a closed system a slurry of said basic GroupII metal compound, a major proportion of the liquid phase of said slurrybeing inert to the desired reaction, introducing into said closed systemsaid basic Group II metal compound and said phosphinodithoic acid, atrates so as to maintain said basic Group II metal compound at everypoint in said system in amounts greatly in excess of the minimum amountsrequired for complete reaction with the amount of said phosphinodithioicacid present at that point, maintaining the temperature of thecontinuously circulating stream of said slurry for a substantial portionof a circulating cycle at a temperature favorable to the desiredreaction and drawing off from the system a liquid product at about itsrate of formation.

2. In the process of reacting a basic Group II metal compound and aphosphorodithioic acid to form a liquid product, the steps ofcontinuously circulating in a closed system a slurry of said basic GroupII metal compound, a major proportion of the liquid phase of said slurrybeing inert to the desired reaction, introducing into said closed systemsaid basic Group II metal compound and said phosphorodithioic acid, atrates so as to maintain said basic Group II metal compound at everypoint in said system in amounts greatly in excess of the minimum amountsrequired for complete reaction with the amount of said phosphorodithioicacid present at that point, maintaining the temperature of thecontinuously circulating stream of said slurry for a substantial portionof a circulating cycle at a temperature favorable to the desiredreaction and drawing off from the system a liquid product at about itsrate of formation.

3. In the process of reacting a zinc oxide and a di-(laurylphenyl)phosphinodithioic acid to form a liquid product, the stepsof continuously circulating in a closed system a slurry of said zincoxide, a major proportion of the liquid phase of said slurry being inertto the desired reaction, introducing into said closed system said zincoxide and said di-(laurylphenyl)phosphinodithioic acid, at rates so asto maintain said zinc oxide at every point in said system in amountsgreatly in excess of the minimum amounts required for complete reactionwith the amount of said di-(laurylphenyl)phosphinodithioic acid presentat that point, maintaining the temperature of the continuouslycirculating stream of said slurry for a substantial portion of acirculating cycle at a temperature favorable to the desired reaction anddrawing off from the system a liquid product at about its rate offormation.

4. In the process of reacting a zinc oxide and a dilauryl phosphoricacid to form a liquid product, the steps of continuously circulating ina closed system a slurry of said zinc oxide, a major proportion of theliquid phase of said slurry being inert to the desired reaction,introducing into said closed system said zinc oxide and said dilaurylphosphoric acid, at rates so as to maintain said zinc oxide at everypoint in said system in amounts greatly in excess of the minimum amountsrequired for complete reaction with the amount of said dilaurylphosphoric acid present at that point, maintaining the temperature ofthe continuously circulating stream of said slurry for a substantialportion of a circulating cycle at a temperature favorable to the desiredreaction and drawing off from the system a liquid product atabout itsrate of formation,

References Cited UNITED STATES PATENTS 1,947,852 2/1934 IeWett 260-698 X2,078,421 4/1937 Shuman 260-461312 2,374,507 4/ 1945 Schulze 260-698 X2,480,673 8/1949 Reilf et al. 260461.113 2,506,310 5/1950 Mikeska260461.113 2,595,170 4/1952 Rudel et a1. 26046l 2,624,750 1/1953Pechukas 260-461.312 2,665,295 1/ 1954 Augustine 26046l 2,738,326 3/1956Anderson et al 260-504 2,862,947 12/1958 Goldsmith 260-461.l13

FOREIGN PATENTS 745,858 3/1956 British.

OTHER REFERENCES Kosolapofl: Organo-Phosphorus Compounds, John Wiley andSons (1950), p. 256.

CHARLES B. PARKER, Primary Examiner. M. LIEBMAN, Examiner.

I. R. GENTRY, RICHARD L. RAYMOND, F. M.

SIKORA, Assistant Examiners.

1. IN THE PROCESS OF REACTING A BASIC GROUP II METAL COMPOUND ANDPHOSPHINODITHIOIC ACID TO FROM A LIQUID PRODUCT, THE STEPS OFCONTINUOUSLY CIRCULATING IN A CLOSED SYSTEM A SLURRY OF SAID BASIC GROUPIIMETAL COMPOUND, A MAJOR PROPORTION OF THE LIQUID PHASE OF SAID SLURRYBEING INERT TO THE DESIRED REACTION, INTRODUCING INTO SAID CLOSED SYSTEMSAID BASIC GROUP II METAL COMPOUND AND SAID PHOSPHINODITHOIC ACID, ATRATES SO AS TO MAINTAIN SAID BASIC GROUP II METAL COMPOUND AT EVERYPOINT IN SAID SYSTEM IN AMOUNTS GREATLY IN EXCESS OF THE MINIMUM AMOUNTSREQUIRED FOR COMPLETE REACTION WITH THE AMOUNT OF SAID PHOSPHINODITHIOICACID PRESENT AT THAT POINT, MAINTAINING THE TEMPERATURE OF THECONTINUOUSLY CIRCULATING STREAM OF SAID SLURRY FOR A SUBSTANTIAL PORTIONOF A CIRCULATING CYCLE AT A TEMPERATURE FAVORABLE TO THE DESIREDREACTION AND DRAWING OFF FROM THE SYSTEM A LIQUID PRODUCT AT ABOUT ITSRATE OF FORMATION.